2 * Copyright (C) 2012 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef ANDROID_FENCE_H
18 #define ANDROID_FENCE_H
21 #include <sys/types.h>
23 #include <ui/ANativeObjectBase.h>
24 #include <ui/PixelFormat.h>
26 #include <utils/Flattenable.h>
27 #include <utils/String8.h>
28 #include <utils/Timers.h>
30 struct ANativeWindowBuffer;
34 // ===========================================================================
36 // ===========================================================================
39 : public LightRefBase<Fence>, public Flattenable
42 static const sp<Fence> NO_FENCE;
44 // TIMEOUT_NEVER may be passed to the wait method to indicate that it
45 // should wait indefinitely for the fence to signal.
46 enum { TIMEOUT_NEVER = -1 };
48 // Construct a new Fence object with an invalid file descriptor. This
49 // should be done when the Fence object will be set up by unflattening
53 // Construct a new Fence object to manage a given fence file descriptor.
54 // When the new Fence object is destructed the file descriptor will be
58 // Check whether the Fence has an open fence file descriptor. Most Fence
59 // methods treat an invalid file descriptor just like a valid fence that
60 // is already signalled, so using this is usually not necessary.
61 bool isValid() const { return mFenceFd != -1; }
63 // wait waits for up to timeout milliseconds for the fence to signal. If
64 // the fence signals then NO_ERROR is returned. If the timeout expires
65 // before the fence signals then -ETIME is returned. A timeout of
66 // TIMEOUT_NEVER may be used to indicate that the call should wait
67 // indefinitely for the fence to signal.
68 status_t wait(unsigned int timeout);
70 // waitForever is a convenience function for waiting forever for a fence to
71 // signal (just like wait(TIMEOUT_NEVER)), but issuing an error to the
72 // system log and fence state to the kernel log if the wait lasts longer
73 // than a warning timeout.
74 // The logname argument should be a string identifying
75 // the caller and will be included in the log message.
76 status_t waitForever(const char* logname);
78 // merge combines two Fence objects, creating a new Fence object that
79 // becomes signaled when both f1 and f2 are signaled (even if f1 or f2 is
80 // destroyed before it becomes signaled). The name argument specifies the
81 // human-readable name to associated with the new Fence object.
82 static sp<Fence> merge(const String8& name, const sp<Fence>& f1,
85 // Return a duplicate of the fence file descriptor. The caller is
86 // responsible for closing the returned file descriptor. On error, -1 will
87 // be returned and errno will indicate the problem.
90 // getSignalTime returns the system monotonic clock time at which the
91 // fence transitioned to the signaled state. If the fence is not signaled
92 // then INT64_MAX is returned. If the fence is invalid or if an error
93 // occurs then -1 is returned.
94 nsecs_t getSignalTime() const;
96 // Flattenable interface
97 size_t getFlattenedSize() const;
98 size_t getFdCount() const;
99 status_t flatten(void* buffer, size_t size,
100 int fds[], size_t count) const;
101 status_t unflatten(void const* buffer, size_t size,
102 int fds[], size_t count);
105 // Only allow instantiation using ref counting.
106 friend class LightRefBase<Fence>;
110 Fence(const Fence& rhs);
111 Fence& operator = (const Fence& rhs);
112 const Fence& operator = (const Fence& rhs) const;
117 }; // namespace android
119 #endif // ANDROID_FENCE_H